Cab repair help

[sirmuppet]

Hi all.

I'm gonna repair my 810 Fender cab. I currently doesn't work and I don't know what's wrong with it. It never worked. I have the 410 version of this cab. Would they be wired the same? As in can I follow the wiring for the 410 and use that as a guide to make sure nothing inside the 810 has been changed?

I already noticed that the first speaker on the 810 was attached different to the 410 in that the cables went on different lugs.

Any suggestions?

Thanks.

[BassBunny]

I would very much doubt they would be wired the same. Depending on the impedance of the speakers will determine how they should be wired and that may be why you have already noticed a difference.
Some more details are really needed.
Is it a 4/8/16 Ohm Cab? What is the impedance of the speakers in the 810? Pictures and any info you can see on the drivers needed. Is there a x-over?

[sirmuppet]

Ok, that's good to know as they are differently wired and I wondered if that was the issue.

The cab I'm trying to get working is a Fender 810 Bassman Neo. This one: http://shop.fender.com/en-GB/bass-amplifiers/pro-tube/bassman-810-neo-enclosure/2249200000.html#start=1 The 810 is a 4ohm cab and has a tweeter.

Speakers look to be the same as in my Neo 410 but they don't have any stickers on them. Only difference (apart from the stickers) is that the foam ring on the front is a softer foam on the 810 than on the 410.

Thanks for the reply.

[sirmuppet]

I've got my multimeter to work. I've test the one speaker I have with me here and on the 200 setting it reads 6.3. I'll need to test the rest of the speakers but can I ask, if the speaker reads 6.3 does that make it an 8ohm speaker? if so is that right for a 4ohm 8x10 cab?

[BigRedX]

Eight 8Ω speakers can be wired up to give a total cab impedance of 4Ω or 8Ω (or 2Ω or 16Ω) depending on how it is done.

You really need to photograph how the cab is currently wired up so that we can advise.

[sirmuppet]

[quote name='BigRedX' timestamp='1508931632' post='3395410']
Eight 8Ω speakers can be wired up to give a total cab impedance of 4Ω or 8Ω (or 2Ω or 16Ω) depending on how it is done.

You really need to photograph how the cab is currently wired up so that we can advise.
[/quote]

No probs. Would a photo of each speaker connection and detailing which speaker it is help? Just I'm not 100% sure the person before me wired it up correctly as it did look like someone had been in it at some point.

[BigRedX]

You need to show how all the wires join all the speakers in the cab together and to the other components like the input sockets and the crossover.

And unless you can guarantee that all the speakers in the cab are the ones originally fitted when it was made, you'll also need to measure the resistance of each one individually, just in case someone has replaced one or more of them with a speaker of a different value.

[sirmuppet]

[quote name='BigRedX' timestamp='1508939467' post='3395506']
You need to show how all the wires join all the speakers in the cab together and to the other components like the input sockets and the crossover.

And unless you can guarantee that all the speakers in the cab are the ones originally fitted when it was made, you'll also need to measure the resistance of each one individually, just in case someone has replaced one or more of them with a speaker of a different value.
[/quote]

Cool, I can do that. I'll take the speakers out and photograph each and note it's location. I'll also test each one and show photos of all the other parts. It may not be today but it won't be a problem to do it.

I think it's probably a good idea for me to test each speaker anyway to make sure they're all working.

[sirmuppet]

Ok here goes

Looking front on at the cab.

Top left speaker connections and test

[url="http://s444.photobucket.com/user/ferengo/media/2017/Basschat/neo_zpsyxs3r1t1.jpg.html"][/url]
[url="http://s444.photobucket.com/user/ferengo/media/2017/Basschat/IMG_5745_zpsiv5xemiv.jpg.html"][/url]

Top Right speaker connections and test


[url="http://s444.photobucket.com/user/ferengo/media/2017/Basschat/IMG_5746_zpsao4hc6e8.jpg.html"][/url]
[url="http://s444.photobucket.com/user/ferengo/media/2017/Basschat/IMG_5748_zpsblhcylhn.jpg.html"][/url]

Second top left speaker connections and test


[url="http://s444.photobucket.com/user/ferengo/media/2017/Basschat/IMG_5754_zpsgzcqnc1i.jpg.html"][/url]
[url="http://s444.photobucket.com/user/ferengo/media/2017/Basschat/IMG_5755_zpsgfhkxiv5.jpg.html"][/url]

Second top right speaker connections and test


[URL=http://s444.photobucket.com/user/ferengo/media/2017/Basschat/IMG_5756_zpsoumuhqml.jpg.html][IMG]http://i444.photobucket.com/albums/qq170/ferengo/2017/Basschat/IMG_5756_zpsoumuhqml.jpg[/IMG][/URL]
[URL=http://s444.photobucket.com/user/ferengo/media/2017/Basschat/IMG_5757_zpsb7aptxcw.jpg.html][IMG]http://i444.photobucket.com/albums/qq170/ferengo/2017/Basschat/IMG_5757_zpsb7aptxcw.jpg[/IMG][/URL]

Second bottom left speaker connections and test


[url="http://s444.photobucket.com/user/ferengo/media/2017/Basschat/IMG_5758_zpsln2usqdb.jpg.html"][/url]
[url="http://s444.photobucket.com/user/ferengo/media/2017/Basschat/IMG_5759_zpswdnolwwy.jpg.html"][/url]

Second bottom right speaker connections and test


[url="http://s444.photobucket.com/user/ferengo/media/2017/Basschat/IMG_5760_zpstmarkoaj.jpg.html"][/url]
[url="http://s444.photobucket.com/user/ferengo/media/2017/Basschat/IMG_5761_zpsi0rdhgmx.jpg.html"][/url]

Bottom left speaker connections and test


[url="http://s444.photobucket.com/user/ferengo/media/2017/Basschat/IMG_5762_zpshyzl8ugw.jpg.html"][/url]
[url="http://s444.photobucket.com/user/ferengo/media/2017/Basschat/IMG_5763_zpsrcqxwahb.jpg.html"][/url]

Bottom right speaker connections and test

[url="http://s444.photobucket.com/user/ferengo/media/2017/Basschat/IMG_5764_zpsph7vxqws.jpg.html"][/url]
[url="http://s444.photobucket.com/user/ferengo/media/2017/Basschat/IMG_5765_zpsikzqpssa.jpg.html"][/url]


I'm guessing this is the crossover?


[url="http://s444.photobucket.com/user/ferengo/media/2017/Basschat/IMG_5752_zpspce74wt8.jpg.html"][/url]
[url="http://s444.photobucket.com/user/ferengo/media/2017/Basschat/IMG_5751_zpshym5dpvb.jpg.html"][/url]
[url="http://s444.photobucket.com/user/ferengo/media/2017/Basschat/IMG_5750_zpsuqpzcorn.jpg.html"][/url]
[url="http://s444.photobucket.com/user/ferengo/media/2017/Basschat/IMG_5749_zps9yt9tfpw.jpg.html"][/url]

Edited October 25, 2017 by sirmuppet

[sirmuppet]

I did a test by putting the tips of the multimeter together and I got a reading of 1. From some sites it says to subtract that reading from that of the speaker and that should give you the rating of the speaker. Since I'm getting between 4.9 & 5.9, subtracting 1 would give me 3.9 to 4.9 making them all 4ohm speakers is that correct?

Also if they are all 4ohm speakers then the cab should be wired in series correct? As it is a 4ohm cab.

Lastly I noticed the crossover has 8ohm on it. What's the deal with that?

Thanks.

[BassBunny]

From your original readings I would have assumed the speakers were [color=#282828][font=helvetica, arial, sans-serif]8Ω and a combination of series/parallel would give you 4[/font][/color][color=#282828][font=helvetica, arial, sans-serif]Ω. [/font][/color]
[color=#282828][font=helvetica, arial, sans-serif]The fact that the x-over has 8[/font][/color][color=#282828][font=helvetica, arial, sans-serif]Ω written on would indicate that it is an [/font][/color][color=#282828][font=helvetica, arial, sans-serif]8[/font][/color][color=#282828][font=helvetica, arial, sans-serif]Ω cab and the speakers are still wired [/font][/color][color=#282828][font=helvetica, arial, sans-serif]series/parallel but a different arrangement.[/font][/color]
[color=#282828][font=helvetica, arial, sans-serif]Need to somehow establish exactly what the impedance should be and the impedance of the speakers.[/font][/color]

[sirmuppet]

[quote name='BassBunny' timestamp='1509011217' post='3395961']
From your original readings I would have assumed the speakers were [color=#282828][font=helvetica, arial, sans-serif]8Ω and a combination of series/parallel would give you 4[/font][/color][color=#282828][font=helvetica, arial, sans-serif]Ω. [/font][/color]
[color=#282828][font=helvetica, arial, sans-serif]The fact that the x-over has 8[/font][/color][color=#282828][font=helvetica, arial, sans-serif]Ω written on would indicate that it is an [/font][/color][color=#282828][font=helvetica, arial, sans-serif]8[/font][/color][color=#282828][font=helvetica, arial, sans-serif]Ω cab and the speakers are still wired [/font][/color][color=#282828][font=helvetica, arial, sans-serif]series/parallel but a different arrangement.[/font][/color]
[color=#282828][font=helvetica, arial, sans-serif]Need to somehow establish exactly what the impedance should be and the impedance of the speakers.[/font][/color]
[/quote]

It's a 4ohm cab. Has it written on the back.

Fender didn't have a diagram to send when I called them. The guy I spoke to went away and looked at a cab and made a diagram for me. He just sent it over. +100 for Fender customer support. I'll post the diagram in a sec and see if it makes sense.

[sirmuppet]

[URL=http://s444.photobucket.com/user/ferengo/media/2017/Basschat/unnamed_zpszmedkfwo.png.html][IMG]http://i444.photobucket.com/albums/qq170/ferengo/2017/Basschat/unnamed_zpszmedkfwo.png[/IMG][/URL]

[sirmuppet]

It's a little hard to see on the original diagram. I've marked which I think are the positive and negative connections. Am I right?

[URL=http://s444.photobucket.com/user/ferengo/media/2017/Basschat/new_zpsv3h2nf8z.jpg.html][IMG]http://i444.photobucket.com/albums/qq170/ferengo/2017/Basschat/new_zpsv3h2nf8z.jpg[/IMG][/URL]

[Phil Starr]

You say the cab has never worked? If so I'd advise you check everything thoroughly before you start any rewiring. Do all the speakers work. It looks like they are all giving the right sort of resistance reading with your meter so that's a good sign but I'd test them all anyway by connecting them each in turn to a signal of about a watt or so to make sure they sound OK without any obvious distortion. You can just use any solid state amp and make up a lead with a couple of bare wires or better still some spade connectors on them. Connect each one up in turn with nothing else connected to the speaker. The volume you are looking for is about that of a domestic radio or TV. You'll lose some bass without the cab intact but you should get an otherwise clear tone out of them. If they all work like this then the fault is with the wires or the socket or possibly a fuse in the little circuit board on the back of the tweeter. Actually in your photo it looks like there might be a fuse missing, just saying....

Anyway each speaker is 8ohms, the nominal impedance is made up of the dc resistance that you have measured plus a little extra due to the inductance of the voice coil which varies with frequency so it's always higher than the DC resistance.

Basically your cab is wired so the adjacent speakers are wired in series + to - making each pair 16ohms These pairs are then wired in parallel making 4ohms overall. All the spare +'s down one side are connected to the orange wire and the spare -'s down the other to the brown - wire. If you wire them up as shown then a test signal connected to the orange and brown wires should get all the 10's singing.

[sirmuppet]

[quote name='Phil Starr' timestamp='1509019023' post='3396055']
You say the cab has never worked? If so I'd advise you check everything thoroughly before you start any rewiring. Do all the speakers work. It looks like they are all giving the right sort of resistance reading with your meter so that's a good sign but I'd test them all anyway by connecting them each in turn to a signal of about a watt or so to make sure they sound OK without any obvious distortion. You can just use any solid state amp and make up a lead with a couple of bare wires or better still some spade connectors on them. Connect each one up in turn with nothing else connected to the speaker. The volume you are looking for is about that of a domestic radio or TV. You'll lose some bass without the cab intact but you should get an otherwise clear tone out of them. If they all work like this then the fault is with the wires or the socket or possibly a fuse in the little circuit board on the back of the tweeter. Actually in your photo it looks like there might be a fuse missing, just saying....

Anyway each speaker is 8ohms, the nominal impedance is made up of the dc resistance that you have measured plus a little extra due to the inductance of the voice coil which varies with frequency so it's always higher than the DC resistance.

Basically your cab is wired so the adjacent speakers are wired in series + to - making each pair 16ohms These pairs are then wired in parallel making 4ohms overall. All the spare +'s down one side are connected to the orange wire and the spare -'s down the other to the brown - wire. If you wire them up as shown then a test signal connected to the orange and brown wires should get all the 10's singing.
[/quote]

Yeah the cab never worked. Well one speaker seemed to. I ended up getting it cheap as an enclosure to basically work on but I used the money I got back and put it towards the 4x10 neo.

I was advised when I put it into the store that the tweeter didn't work but upon opening it they found a fuse blown and a spare fuse clipped onto the side. When they put the spare in the tweeter started working. I'll get another and pop it into the spare section anyway, you never know.

As for testing the speakers, that seems a bit beyond me. Would the 9v battery test be a decent alternative?

Cheers for the advice to everyone so far.

[sirmuppet]

Another quick question. How would I test the cables connecting the speakers within the cab? I have the multimeter but am trying to find how to test for broken cables and all anyone is showing is a polarity test which doesn't apply here. All I'd like to do is check one end to the other and make sure the cable is functioning like it should. What would the setting be for that?

Thanks,

[BassBunny]

[quote name='sirmuppet' timestamp='1509028727' post='3396165']
Another quick question. How would I test the cables connecting the speakers within the cab? I have the multimeter but am trying to find how to test for broken cables and all anyone is showing is a polarity test which doesn't apply here. All I'd like to do is check one end to the other and make sure the cable is functioning like it should. What would the setting be for that?

Thanks,
[/quote]
Same setting as you used to test resistance. If the cable is OK resistance will be "zero". If it is broken there won't be a reading.
It might be worth indicating where you are located as there is a list of people somewhere on the site who are happy to help with repairs etc. and it might be an idea to enlist some help.

[sirmuppet]

[quote name='BassBunny' timestamp='1509036883' post='3396239']
Same setting as you used to test resistance. If the cable is OK resistance will be "zero". If it is broken there won't be a reading.
It might be worth indicating where you are located as there is a list of people somewhere on the site who are happy to help with repairs etc. and it might be an idea to enlist some help.
[/quote]

Cheers, I used the setting and tested all the leads. The speakers and cables were all working correctly. I followed the wiring diagram and success! It's fully working.

Just wanted to take a moment to say thanks for all the advice on here. It's been really helpful in testing the parts and making sure I don't do the wrong thing.

[BassBunny]

[quote name='sirmuppet' timestamp='1509051765' post='3396380']
Cheers, I used the setting and tested all the leads. The speakers and cables were all working correctly. I followed the wiring diagram and success! It's fully working.

Just wanted to take a moment to say thanks for all the advice on here. It's been really helpful in testing the parts and making sure I don't do the wrong thing.
[/quote]
I love a plan when it comes together.